Make improvements to existing Tableau visualisation.
For the Dataviz Makeover exercise, the task is to critic and make improvements on the existing Tableau visualisation that can be found here. The visualisation shows the total number of bus trips that starts and ends from a subzone in Singapore based on either weekday or weekends and holidays by the time of hour of the day. Another visualisation shows the adjacency matrix of the percentage of total trips from a subzone for the different destination subzones in Singapore. The purpose of the visualisation is to see how the public bus transport network is like in Singapore.
The main title and subtitles are important for users to understand the purpose of the dashboard. It should consist of a short write up on what users can discover from the dashboard.
The Day Type labels for the column charts have been cut off for weekends/holiday. Placing them at 90 degrees will help to show the entire axis label clearly.
Having a mean line to show the average number of trips to and from a subzone would be a good reference for people to gauge which hours in the day have higher or lower total trips.
NULL values do not show any useful information for users and it can be confusing to users who do not know what it means and its purpose in the chart. It can be omitted out to reduce clutter as well as there are many subzones for users to select.
The time in the scale does not start at 0. This will give users the wrong impression that there are no midnight bus trips which is untrue based on the data given.
The subtitle of each chart is used to give a short and clear description on what is represented by the chart. Without it, the user might not know what the chart is trying to convey.
The adjacency matrix is too cramp to be able to see the colour differences in the matrix. The colour differences are important to see the differences in the percentage of total bus trips between different destination subzones for each origin subzone for users to do comparison.
The adjacency matrix for weekend/holiday plot has been cut off and does not show all the data. This means that the information shown is incomplete and hence, have to be fixed to provide a full picture for users. One reason why it might have been cut off is probably due to the very large adjacency matrix as it is showing all Originz subzone and Destination subzone.
No subzone labels can be seen for both axis. Either it is too small to be seen or it has been omitted, the label should be shown clearly for users to easily identify the origin or destination subzone for easier referencing when looking at the adjacency matrix.
The weekday and weekend/holiday barcharts have the same colour, making it hard for users to differentiate them. Using different colours for each chart will make it easier for reading and with colours, the day type axis labels can be removed. A small legend will be used instead. Using the same colour scheme for all charts for weekdays and weekend/holidays throughout the dashboard also allows user to easily pick out the visualisation of interest more readily.
The title of the adjacency matrix does not clearly show that the information shown is only for trips from Origin subzone to Destination subzone. This makes it difficult for users to understand what the numbers mean. It would be better to state in the chart title which percent total has been calculated.
Without a map of Singapore, for people who are unfamiliar with the subzones in Singapore, it would be hard to see trends of bus trips in different regions of Singapore. Having a map of Singapore and showing the adjacency matrix on the map would give a better perspective of how the public bus network is like in Singapore for different subzones.
Having a proper text for each element in the tool tips will help user understand the data better. The last information, ‘% of Total Total Trips along Table (Across)’ is not clear on what the percentage value is about. It would be better to change it to ‘% of Total trips from Origin Subzone’.
Currently, all subzones are shown for the adjacency matrix. It would be better to allow users to filter subzones based on origin subzone. This would allow users to filter based on which subzones they are interested in and easily see the differences in the percent total of trips between the different destination subzones.
For the alternative data visualisation, the focus will be to fix the issues on clarity and aesthetics that were mentioned above.
The charts will still be split by weekdays and weekends/holidays, however, blue colour will be used to represent charts that belong to weekdays and for weekends/holidays, orange will be used. This would enable users to easily identify which charts belong to the same ‘Day type’. The same colour scheme will be applied on the adjacency matrix. Using colour to differentiate the Day Type will also help to provide more space for the charts as the axis labels can be removed.
The adjacency matrix will now be shown in the form of a map of Singapore. A filter will be used for user to select the Origin subzone of interest. This filter will be linked to the ‘Total Bus Trips from < Origin_sz >’ barchart for better interactivity.
A main title and subtitle of the dashboard will be added to explain the overall purpose for it and descriptions will be added in the subtitles for each of the charts and the purpose behind them will be added as well.
A reference line showing the average number of bus trips will be added to the barcharts to give user a better idea on which hours of the day have higher or lower number of bus trips.
The Time of the day (Hours) axis will include the midnight hours which are missing in the current data visualisation to give a clearer picture on the trends of bus trips throughout the day.
The final visualisation dashboard is shown below. It can also be found here
Observing the adjacency matrix for both weekdays and weekends, the darker colours are usually found just outside of the origin subzone. The bus trips going out of the subzones are mostly in the same planning region with a few trips that go much further out of 2 subzone radius. This is probably due to the Land Transport Authority’s new master plan for 2040 to have a 45-Minute City with 20-Minute towns. To achieve this, public transports, including public buses, will have to provide a more seamless connection. The public bus transport purpose is therefore used to increase connectivity within a town while the MRT is used to connect between towns.
Another observation is that the peak hours for public buses in residential subzones like Kovan are at 7am and 6pm which coincides with the timing when people go to work and get off from work on weekdays. As for weekends, there is no extreme peaks seen as compared to weekdays as most people do not work on weekends. An interesting observation is that the total bus trips barchart from a subzone and to a subzone has a general trend where they are somewhat mirror images of each other. This makes sense as most people will have to go out of their subzones to get to work in the morning and by evening, they will be taking the bus home towards the subzone where they stay. It shows how the bus trips have been arranged to cater to the needs of the subzone during the peak hours on weekdays. As for weekends, there are generally more bus trips in and out of the subzones from 10am to 8pm where people will be going out during the weekends during this period of the day. Below shows the total bus trips from and to Kovan throughout the day.
The graph will look like below after making the above changes.
The graph will look as shown below after making the changes.
We will have to create the adjacency matrix for both weekday and weekend/holiday. The following steps will be done for weekday. For weekend/holiday, a new sheet will be duplicated but the Day Type will be selected as Weekend/Holiday instead of Weekday.
To create the adjacency matrix, we will first pull the Total Trips into Color so as to use colours to differentiate how many trips are going out from the subzone. The lighter the colour, the lesser the number of bus trips. Next, pull Destination Sz into Detail to show the names of each subzone on the map in Tooltips.
In the Table Calculation box, change Calculation Type to ‘Percent of Total’ and close the window.
7.To allow users to filter by subzone, Origin Sz Set which was created earlier to remove NULL option will be dragged into the Filters section. Click on the arrow of Origin Sz Set under Filters and select Show Filter. Once filter appears on the right most, click the arrow of the shown filter and select Single Value (List) to restrict it to show only 1 choice.
Duplicate the current worksheet to create the adjacency matrix for weekend/holiday. This time, change the Day Type to weekend/holiday and colour scheme from Blue to Orange
To link the Origin Sz Set filter to all worksheets that are using it , we will have to apply the filter to other worksheet using the same column as a filter. Clink on the small arrow at Origin Sz Set filter, go to Apply to Worksheets and select Selected Worksheets.
Select both adjacency matrix worksheet and the Trips from worksheet that uses the Origin Sz Set filter and click OK.